Pipe bending machine



April 3, 1956 Filed June 14, 1948 J. L. COODY PIPE BENDING MACHINE 3 Sheets-Sheet l ATTORNEY.

April 3, 1955 i J. L. COODY 2,740,452

PIPE BENDING MACHINE Filed June 14, 1948 3 Sheets-Sheet 2 1L l b I3 20 II l0 l1 l1 3 Mfi w 3 1 i Z 2 7 4 l 5M. 12%; g M #M ATToRNEY April 3, 1956 J. COODY 2,740,452

PIPE BENDING MACHINE Filed June 14, 1948 3 Sheets-Sheet 3 INVENTOR.

ATTOR EY PEPE BENDING MACHINE John L. Coody, Houston, Tex., assignor, by mesne assignments, to Cinch, Ina, Fort Smith, Arie, a corpo ration of Arkansas Application June 14, 1948, Serial' No. 32,911

Claims. ((3153-32) This invention relates to a pipe bending machine.

An object of the invention is to provide a power operable machine of. the character described particularly designed for bending heavy pipe and useful in the construction of pipe lines. which follow a varying course; however, the machine is capable of general use and may be adapted to pipe of various sizes.

Another object of the invention isv to provide a pipe bending machine in which a considerably greater; leverpipe will be maintained substantially round at the bend.

Another object of this invention is to provide a. pipe bending machine in which a considerably greater leverage can be exerted in bending a pipe than has heretofore been possible without danger of bending the pipe at an undesired position.

Another object is to provide a pipe bending machine which will make it possible to form a pipe into a curved die without necessity for employing a fixed pivotal support for the forming mechanism at substantially the center of curvature of the bend to be made in the pipe, thereby making possible bends on very long radii without the use of excessively large machines. 7

Another object is to provide a machine which. will make possible the bending ofa pipe into a curved die to cause it to conform thereto, in which the curvature of the die and hence of the bend to be formed in the pipe may not be of uniform radius throughout the extent of g the bend.

In accordance with this invention provision has been made for preventing the wrinkling of the pipe on the inside of the bend.

The machine is of such construction that it is adapted for use in the field where various earth contours and various conditions, are encountered.

Other objects and advantages will be apparent from the following specification which is illustrated by the accompanying drawings wherein:

Figure l is a plan view of one embodiment of the machine.

Figure 2 is a side elevation thereof.

Figure 3 is an end elevation as viewed in the direction indicated by the line 33 of. Figure 2.

Figure 4 is an end elevation as viewedin the direction indicated by the line 44 of Figure 2..

Figure 5 is a diagrammatic plan view of the fluid pres.- sure power applying means employed.

Figure 6 is a perspective view of one form of a. holding shoe employed.

Figure 7 is a fragmentary perspective view of another form of holding shoe employed.

Referring now more particularly to the. drawings, wherein like numerals of reference designate similar-parts in each of the figures, the numerals: 1, 1 designate similar parallel runners on which are the spacing blocks 2 and on the blocks are mounted the side members 3 connected by the cross beams 4, 4; 5, 5 and 6, 6, thus form ing a supporting skid which supports the bending equip- 2. meat and whereby it may be readily moved over the ground surface from place to place.

There are the front and rear horizontal rollers 7' and 8 which are mounted on the front and rear cross beams 4 and 6, respectively, and there is an intermediate roller 9 on the front cross beam: 5.

These rollers are above the upper surface of the skid and are provided to support the pipe 10' to be bent and to facilitate the longitudinal movement ofthe pipe as the successive bending operations are performed.

Slidable on the cross beams 4, 4 there is an upstanding bracket 11 and'pivoted to the inner side ofsai'd' bracket, on a vertical axis, there is a holding shoe 12. This holding shoe is of sufiicient length to give the required strength and its forward, or operative face, is semicylindrical so as" to snugly receive the pipe 1%,, as shown in Figure 3; however the holding shoe 12:: may be pivoted' to the crossbeams 4, as shownin Figure 6,. in which case a latch bar, as 16b may be employedto latch it in active position.

Off-set rearwardly from the holding shoe 12, there is a bending die 13 whose inner side, that is the side towardthe pipe, is of semi-cylindrical shape to receive the. pipe and this die is also curved longitudinally from end to end to cause the pipe to bend accordingly to the longitudinal curvature of the die upon the application of power to the pipe as hereinafter explained.

This bending die may be provided with spaced, circumferential external ribs as 14 and also may have external longitudinal ribs 15, said ribs. being provided to give the die the required, strength.

During. the bending operation the die 13 is securely held. in place by means of transverse bars as 16 which are secured, at one end to the die 13, as indicated in Figure 1 and whose other ends are secured to the upper ends of standards 17, 17, 17a which are suitably anchored to the skid on the. opposite side of'the pipe from the die asbest indicated in Figures 1 and. 2.

The die is thereby held in immovable position during the bending operation.

As indicated in Figure l the holding shoe 1'2 is'on. the opposite side of the pipe from the die and is spaced longitudinally forwardly of the die. The bending power is to be applied to the pipe, as hereinafter explained, on the opposite side of the die from the holding shoe.

The numeral 18 designates a straight axis power applying shoe employed. This shoe is of a general cylindrical shape and may be reenforced, externally, in, the same manner as the die 13. Its inner side, that is the side. toward the pipe, is semi-cylindrical to fit closely about the pipe. It is somewhat longer than the die13 and, as shown in Figure 1, the die 13 and the shoe 18 are arranged in staggered relation and are on opposite sides of the pipe with their ends. over-lapping, This shoe is mounted to slide laterally on the skid toward and away from the die 13. i

The numerals i9 andZt) designate pressure. cylinders the former of which is pivotally connected to an upstanding anchor 21 which. isv fixed to a side member 3: of the. supporting framework and the latter of which is pivotally connected to. the standard 17a. These cylinr ders are equipped with conventional pistons extended our: wardly from which are the piston rods" 23 and? 2.4;. outer ends of these rods are pivotally connected to the shoe 18, the former being connected near the rear, end of the shoe and the latter being connected: to' an intermediate point of the shoe.

With the pipe 10 to be bent mounted on the rollers '7', Sand 9 the pipe will assume the position indicated in dotted lines in Figure 1 with the pistons and piston rods- 23 and 24 retracted. The holding shoe Will first be advanced to engage the pipe and hold it in snug engagement with the adjacent end of the bending die 13 and then locked in such position as hereinafter described. Pressure may then be applied to cylinders 19 and 2 and transmitted to the pipe and this will force the corresponding portion of the pipe over into the bending die until it occupies the position indicated in full lines in Figure l causing the pipe within the die 13 to bend to the shape of said die.

.As hereinabove indicated both the die and the shoe are substantially semi-cylindrical on the inner sides so that each, where it fully enga es the pipe, will fit snugly almost one half the way around the pipe. The pipe is bent progressively into die 13 from the left end of the die as seen in Fig. 1 to the right end of such die, and at all times at the exact location where the bend is taking place, it will be fully engaged by both die 18 and the die 13 and substantially completely encircled by them. Therefore, as the pipe is bent it will be retained in its original shape in cross section. Necessarily the material of the pipe on the inner side of the bend will be somewhat compressed but it will be retained by the die 13 against wrinkling.

By releasing the pressure in the cylinders 19, 20 the shoe will be released from the pipe whereupon the holding shoe may be backed off and the pipe will then be moved the required distance to the left, as indicated in Figure l, and pressure may then again be applied to the cylinders 19, 28 and an additional bend performed and the successive movements and bending operations may then be repeated until the pipe is bent to the required shape.

For the purpose of conveniently moving the pipe lengthwise, as above indicated, a pressure cylinder has been provided. In this cylinder there is a piston 26 having a piston rod 27 connected thereto and extended outwardly through a stufiing box at the rear end of the cylinder. A suitable cable may be connected, at one end, to said piston rod 27 with a hook 29 at its other end to be engaged with the corresponding end of the pipe, and pressure may be admitted into the cylinder 25 to the rear of the piston 26 and the pipe thus moved along the rollers 7, 8, and 9 the required distance for each bending operation.

The equipment for applying pressure to and relieving the same from the cylinders 19, 20, and 25 will be hereinafter described more in detail.

In mounting the pipe 10 on the machine the end of the pipe section is supported on the roller 8 and the book 29 engaged over the outer end of the pipe. The holding shoe 12a, as shown in Figure 6, or the holding shoe 12, as shown in the other figures, is retracted. Pressure is then applied to the cylinder 25 alternately on opposite sides of the piston 26 to reciprocate said piston and its piston rod 27 and the cable 28 is gradually taken up, or shortened, between the piston rod 27 and the hook 29, in any selected manner, so that the pipe will be gradually advanced and when it is in position on the rollers 7, 8 and 9 and the bending operation is ready to begin the holding shoe 12, or 12a, whichever is used, is then moved into active position against the forward end of the pipe.

In order to move the holding shoe 1?. there is mounted on one of the cross beams 4 a fixed rack 33 and in mesh therewith there is a gear 34 which is suitably mounted on the bracket 11 and which may be rotated by means of a handle 35 which may be detachably connected, in any conventional manner, with the shaft 36 on which the gear wheel 34 is fixed so that said holding shoe 12 may be moved outwardly-or inwardly.

Fixed on the skid 3 out beyond the outer end of the bracket 11 there is an upstanding fixed stop 37 which limits the outward movement of said bracket and holding shoe but when the bracket is moved inwardly so that the holding shoe is against the pipe it may be maintained in its inner position by means of removable blocks, such as 38, inserted between the outer end of the bracket 11 and the stop 37, as indicated in Figures 1, 2 and 7.

For the purpose .of supplying pressure there is mounted on the skid a suitable motor of any selected type, as 39, which is operatively connected to and drives a compressor 40. This compression system, omitting the motor, is shown partly diagrammatically in Figure 5, and includes a pressure tank 41. The compressor takes the pressure fiuid from the tank 41 and delivers it through the pipe 42 and the pipes 43 and branches thereof 43a and 43b to either side of the piston 26. There is a manually operated two way valve 44 which controls the lines 43a, 43b and this valve also controls the relief line 45 so that when the pressure is applied to the cylinder 25 on one side of the piston the pressure will be relieved from the other side and returned into the tank 41 through the return line 46.

The compressor 40 is connected with the cylinders 19, 28 on the forward sides of their pistons through the lines 42, 47 and the branch lines 48a, 48b and is connected with said cylinders 19, 20 on the rear sides of their pistons through the lines 42, 49 and the branch lines 49a, 4%. These lines are controlled by means of a two way valve 50 similar to the valve 44. This valve may be operated to deliver pressure into the cylinders 19, 20 on either side of their pistons and relieved from the other sides of the pistons through the relief line 46 depending'on the operation of the valve 50. The pressure line 42 is also connected into the cylinder 31 on opposite sides of its piston through the branch lines 51, 52 which are controlled by a two way valve 53 similar to the valve 44. By manipulation of the valve 53 fluid pressure may bev admitted into the cylinder 31 on either side of its piston and simultaneously relieved from the other side and returned into the relief line 46 through the line 54 which is connected into the valve 53 and into the relief line. 46. I i t The drawingsand description disclose what is now considered to be preferred forms of the invention by way of illustration only and not by way of limitation while the principle of the invention will be defined by the appended claims.

' What I claim is:

1. in a pipe bender, a support, a curved bending die anchored on the support and having a bend forming face portion, a rockably mounted holding shoe adjacent one end of the die for holding a pipe in engagement therewith, a separate independently mounted stili straight bending shoe having a part extending toward the holding shoe past the central point of the face of and directly opposing the die and overlying the bend forming face portion and a part projecting beyond the bend forming face portion in a direction away from said holding shoe, said bending shoe being free to move toward and from the die and to roll-without slippage along the die, power means comprising two force applying means having spaced independent swinging connections to the bending shoe and spaced independent swinging connections to the support, one such force applying means which is closer to the holding shoe being disposed on the opposite side of the central point of the bending die from the holding shoe to urge a part of the bending shoe directly toward the die to tightly embrace a pipe held therebetween and the other such force applying means being disposed beyond the die on the opposite side from the holding shoe to roll the bending shoe along the die while it is held in such pipe embracing relation with the die, and actuating means operable to cause said two force apply ing means to act conjointly on the bending shoe.

2. A pipe bending machine comprising a support, a rigid die anchored on the support and having a working face with a bend forming portion shaped to conform to the curvature of the inside of the bend to be produced in a pipe, at rockably mounted holding shoe on the support opposed to the curved die adjacent one end thereof and movable toward and away from the curved die, a separate independently mounted rigid bending shoe shaped to conform to the shape of the pipe before bending and having a first part directly opposed to the bend forming portion of the working face of the curved die and extending past the central point of the face of the die toward the holding shoe and a second part located and extending a substantial distance beyond the bend forming portion of said face in a direction away from the holding shoe, and power means comprising two spaced extensible and contractible force applying mechanisms separately swingably connected to said support, one such mechanism which is closer to the holding shoe being swingably connected to the bending shoe on the opposite side of the central point of the bending die from the holding shoe and acting toward the die to cause the bending shoe and curved die to tightly embrace a pipe at the locus of bending during the bending operation while permitting the bending shoe to roll with respect to the die and the other such mechanism swingably connected to said second part of the bending shoe remote from the die and acting transversely of the bending shoe in a direction to roll the bending shoe around the die while the bending shoe is held by said first mechanism in position to act with the die to tightly embrace a pipe being bent, the bending shoe being free for movement within limits in any direction in which it may be urged by said mechanisms and the pipe during the bending operation, and actuating means operable to cause said two force applying mechanisms to act conjointly on the bending shoe.

3. A pipe bending machine comprising a support, a rigid die anchored on the support and having a working face with a bend forming portion shaped to conform to the curvature of the inside of the bend to be produced in a pipe, a rockably mounted holding shoe on the support opposed to the curved die adjacent one end thereof and movable toward and away from the curved die, a separate independently mounted rigid bending shoe shaped to conform to the shape of the pipe before bending and having a first part directly opposed to the bend forming portion of the working face of the curved die and extending past the central point of the face of the die toward the holding shoe, and a second part located and extending a substantial distance beyond the bend forming portion of said face in a direction away from the holding shoe, and power means comprising two spaced extensible and contractible force applying mechanisms separately swingably connected to said support, one such mechanism which is closer to the holding shoe being swingably connected to the bending shoe adjacent the junction between said first and second part of the bending shoe and acting toward the die to cause the bending shoe and the curved die to tightly embrace a pipe at the locus of bending during the bending operation while permitting the bending shoe to roll with respect to the die and the other such mechanism swingably connected to said second part of the bending shoe remote from the die and acting transversely of the bending shoe in a direction to roll the bending shoe around the die while the bending shoe is held by said first mechanism in position to act with the die to tightly embrace a pipe being bent, the bending shoe being free for movement within limits in any direction in which it may be urged by said mechanisms and the pipe during the bending operation, and actuating means operable to cause said mechanisms to act conjointly on said bending shoe.

4. In a pipe bender, a support, a curved bending die anchored on the support and having a bend forming face portion, a rockably mounted holding shoe adjacent one end of the die for holding a pipe in engagement therewith, a separate independently mounted stiff straight bending shoe having a part extending toward the holding shoe past the central point of the face of and directly opposing the die and overlying the bend forming face portion and a part projecting beyond the bend forming face portion in a direction away from said holding shoe, said bending shoe being free to move toward and from the die and to roll without slippage along the die, power means comprising two force applying means having spaced independent swinging connections to the bending shoe in fixed positions thereon and spaced independent swinging connections to the support, one such force applying means which is closer to the holding shoe being disposed on the opposite side of the central point of the bending die from the holding shoe to urge a part of the bending shoe directly toward the die to tightly embrace a pipe held therebetween and the other such force applying means being disposed beyond the die on the opposite side from the holding shoe to roll the bending shoe along the die while it is held in such pipe embracing relation with the die, and actuating means operable to cause said two force applying means to act conjointly on the bending shoe.

5. In a pipe bender, a support, a curved bending die anchored on the support and having a bend forming face portion, a rockably mounted holding shoe adjacent one end of the die for holding a pipe in engagement therewith, a separate independently mounted stiff straight bending shoe having a part extending toward the holding shoe past the central point of the face of and directly opposing the die and overlying the bend forming face portion and a part projecting beyond the bend forming face portion in a direction away from said holding shoe, said bending shoe being free to move toward and from the die and to roll without slippage along the die, power means comprising two force applying means having spaced independent swinging connections to the bending shoe and spaced independent swinging connections to the support, one such force applying means which is closer to the holding shoe being disposed on the opposite side of the central point of the bending die from the holding shoe to urge a part of the bending shoe directly toward the die to tightly embrace a pipe held therebetween and having its swinging connection to the support spaced from the die face portion a distance which is less than the radius of curvature of said die face portion and the other such force applying means being disposed beyond the die on the opposite side from the holding shoe to roll the bending shoe along the die while it is held in such pipe embracing relation with the die, and actuating means operable to cause said two force applying means to act conjointly on the bending shoe.

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